This application relates to a unique method of providing a localization signal to each of the several tire pressure monitoring locations on a vehicle. In particular, the present invention provides localization signals at different time periods for each of the several tires, and which can be associated with a particular location.
Tire pressure monitoring systems are becoming widely utilized in modern vehicles. In a tire pressure monitoring system, a tire pressure sensor is implanted in a vehicle tire. The pressure sensor is sensitive to the air pressure within the tire, and can send a signal should that tire pressure vary from a desired pressure. In one common type of tire pressure sensor, a signal is sent periodically to a central control. The signal includes tire pressure information, and an identifier signal. A control must associate the identifier signal with a particular location, such that a display in the vehicle can report the location of a tire that is experiencing a pressure other than that which is desired.
Various ways of associating the location with the identifier signal, or “localization,” are known in the prior art.
One known method of localization involves the use of an LF signal. An LF signal is typically not utilized to send the tire pressure information from the sensor to the control, but is instead only utilized for localization. Thus, it is known to have tire pressure sensors which periodically report on an RF level, but which are also sensitive to be actuated by an LF “ping” or actuation signal to send a signal that is utilized only for localization purposes.
Once the tire location is known, it is stored in a control, however, various real world aspects such as tire rotation or replacement must make the system able to be updated for new locations. One type of LF localization system uses a handheld device that is brought to each of the tires on the vehicle each time the tires are changed or rotated. This is somewhat undesirable in that a worker associated with the location where the tires are moved must remember to do the localization.
Permanent LF initiators have also been proposed. These can be of two types. A first type has a central LF initiator location that sends out a signal, and some directional algorithm may be utilized to determine the location of the responding signal. With such a system, the strength of the “ping” is undesirably high.
Alternatively, it has also been proposed to have LF initiators associated with each of the tires, and have each of the LF initiators include a receiver that connects into the vehicle data bus. However, it is somewhat undesirable to have the vehicle data bus need to communicate with each of the four tire locations.
Thus, a need exists in the prior art for a system that may be easily utilized to provide localization signals.